Merge branch 'rightlib' into mergelibs-241120-1113

24 files changed, 334 insertions, 440 deletions

diff --git a/library/cpp/lwtrace/rwspinlock.h b/library/cpp/lwtrace/rwspinlock.h
index 5e4608e0683..1effd5fe0e7 100644
--- a/library/cpp/lwtrace/rwspinlock.h
+++ b/library/cpp/lwtrace/rwspinlock.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include <library/cpp/deprecated/atomic/atomic.h>
+#include <atomic>
 
 #include <util/system/spinlock.h>
 
@@ -27,16 +27,16 @@
 //    * writer can release lock (State = 0: -> READING)
 
 struct TRWSpinLock {
-    TAtomic State; // must be initialized by 'TRWSpinLock myLock = {0};' construction
+    std::atomic_signed_lock_free State;
 
     void Init() noexcept {
-        State = 0;
+        State.store(0, std::memory_order_relaxed);
     }
 
     void AcquireRead() noexcept {
         while (true) {
-            TAtomic a = AtomicGet(State);
-            if ((a & 1) == 0 && AtomicCas(&State, a + 2, a)) {
+            std::atomic_signed_lock_free::value_type a = State.load(std::memory_order_acquire);
+            if ((a & 1) == 0 && State.compare_exchange_strong(a, a + 2, std::memory_order_acquire)) {
                 break;
             }
             SpinLockPause();
@@ -44,25 +44,29 @@ struct TRWSpinLock {
     }
 
     void ReleaseRead() noexcept {
-        AtomicAdd(State, -2);
+        State.fetch_add(-2, std::memory_order_release);
     }
 
     void AcquireWrite() noexcept {
         while (true) {
-            TAtomic a = AtomicGet(State);
-            if ((a & 1) == 0 && AtomicCas(&State, a + 1, a)) {
+            std::atomic_signed_lock_free::value_type a = State.load(std::memory_order_acquire);
+            if ((a & 1) == 0 && State.compare_exchange_strong(a, a + 1, std::memory_order_acquire)) {
                 break;
             }
             SpinLockPause();
         }
 
-        while (!AtomicCas(&State, TAtomicBase(-1), 1)) {
+        while (true) {
+            std::atomic_signed_lock_free::value_type a = 1;
+            if (State.compare_exchange_strong(a, -1, std::memory_order_acquire)) {
+                break;
+            }
             SpinLockPause();
         }
     }
 
     void ReleaseWrite() noexcept {
-        AtomicSet(State, 0);
+        State.store(0, std::memory_order_release);
     }
 };
 
diff --git a/library/cpp/netliba/v6/udp_address.cpp b/library/cpp/netliba/v6/udp_address.cpp
index ba5fd6f45b1..be823e2dfa3 100644
--- a/library/cpp/netliba/v6/udp_address.cpp
+++ b/library/cpp/netliba/v6/udp_address.cpp
@@ -196,7 +196,7 @@ namespace NNetliba {
                 continue;
             }
             if (ptr->Mtu < 1280) {
-                fprintf(stderr, "WARNING: MTU %d is less then ipv6 minimum", ptr->Mtu);
+                fprintf(stderr, "WARNING: MTU %lu is less then ipv6 minimum", ptr->Mtu);
             }
             for (IP_ADAPTER_UNICAST_ADDRESS* addr = ptr->FirstUnicastAddress; addr; addr = addr->Next) {
                 sockaddr* x = (sockaddr*)addr->Address.lpSockaddr;
diff --git a/library/cpp/pop_count/benchmark/main.cpp b/library/cpp/pop_count/benchmark/main.cpp
deleted file mode 100644
index 1af2d157b61..00000000000
--- a/library/cpp/pop_count/benchmark/main.cpp
+++ /dev/null
@@ -1,82 +0,0 @@
-#include <util/stream/output.h>
-#include <util/datetime/cputimer.h>
-#include <util/system/type_name.h>
-
-#include <library/cpp/pop_count/popcount.h>
-#include <library/cpp/testing/benchmark/bench.h>
-
-#include <bit>
-
-template <class F, class I>
-inline void DoRun(F&& f, I&& i) {
-    const ui64 n = i.Iterations();
-
-    for (ui64 j = 0; j < n; ++j) {
-        Y_DO_NOT_OPTIMIZE_AWAY(f(j * (ui64)123456 + (ui64)1));
-    }
-}
-
-Y_CPU_BENCHMARK(PopCount_8, iface) {
-    DoRun([](ui8 x) {
-        return PopCount<ui8>(x);
-    },
-          iface);
-}
-
-Y_CPU_BENCHMARK(std_popcount_8, iface) {
-    DoRun([](ui8 x) {
-        return std::popcount<ui8>(x);
-    },
-          iface);
-}
-
-Y_CPU_BENCHMARK(PopCount_16, iface) {
-    DoRun([](ui16 x) {
-        return PopCount<ui16>(x);
-    },
-          iface);
-}
-
-Y_CPU_BENCHMARK(std_popcount_16, iface) {
-    DoRun([](ui16 x) {
-        return std::popcount<ui16>(x);
-    },
-          iface);
-}
-
-Y_CPU_BENCHMARK(PopCount_32, iface) {
-    DoRun([](ui32 x) {
-        return PopCount<ui32>(x);
-    },
-          iface);
-}
-
-Y_CPU_BENCHMARK(std_popcount_32, iface) {
-    DoRun([](ui32 x) {
-        return std::popcount<ui32>(x);
-    },
-          iface);
-}
-
-Y_CPU_BENCHMARK(PopCount_64, iface) {
-    DoRun([](ui64 x) {
-        return PopCount<ui64>(x);
-    },
-          iface);
-}
-
-Y_CPU_BENCHMARK(std_popcount_64, iface) {
-    DoRun([](ui64 x) {
-        return std::popcount<ui64>(x);
-    },
-          iface);
-}
-
-#if !defined(_MSC_VER)
-Y_CPU_BENCHMARK(BUILTIN_64, iface) {
-    DoRun([](ui64 x) {
-        return __builtin_popcountll(x);
-    },
-          iface);
-}
-#endif
diff --git a/library/cpp/pop_count/benchmark/ya.make b/library/cpp/pop_count/benchmark/ya.make
deleted file mode 100644
index e7ea9418db5..00000000000
--- a/library/cpp/pop_count/benchmark/ya.make
+++ /dev/null
@@ -1,12 +0,0 @@
-Y_BENCHMARK()
-
-PEERDIR(
-    util/draft
-    library/cpp/pop_count
-)
-
-SRCS(
-    main.cpp
-)
-
-END()
diff --git a/library/cpp/pop_count/popcount.cpp b/library/cpp/pop_count/popcount.cpp
deleted file mode 100644
index 49276424be1..00000000000
--- a/library/cpp/pop_count/popcount.cpp
+++ /dev/null
@@ -1,30 +0,0 @@
-#include "popcount.h"
-
-#include <util/system/defaults.h>
-#include <util/system/yassert.h>
-
-#include <string.h>
-
-static const ui8 PopCountLUT8Impl[1 << 8] = {
-#define B2(n) n, n + 1, n + 1, n + 2
-#define B4(n) B2(n), B2(n + 1), B2(n + 1), B2(n + 2)
-#define B6(n) B4(n), B4(n + 1), B4(n + 1), B4(n + 2)
-    B6(0), B6(1), B6(1), B6(2)};
-
-ui8 const* PopCountLUT8 = PopCountLUT8Impl;
-
-#if !defined(_MSC_VER)
-//ICE here for msvc
-
-static const ui8 PopCountLUT16Impl[1 << 16] = {
-#define B2(n) n, n + 1, n + 1, n + 2
-#define B4(n) B2(n), B2(n + 1), B2(n + 1), B2(n + 2)
-#define B6(n) B4(n), B4(n + 1), B4(n + 1), B4(n + 2)
-#define B8(n) B6(n), B6(n + 1), B6(n + 1), B6(n + 2)
-#define B10(n) B8(n), B8(n + 1), B8(n + 1), B8(n + 2)
-#define B12(n) B10(n), B10(n + 1), B10(n + 1), B10(n + 2)
-#define B14(n) B12(n), B12(n + 1), B12(n + 1), B12(n + 2)
-    B14(0), B14(1), B14(1), B14(2)};
-
-ui8 const* PopCountLUT16 = PopCountLUT16Impl;
-#endif
diff --git a/library/cpp/pop_count/popcount.h b/library/cpp/pop_count/popcount.h
deleted file mode 100644
index 3d67737ed25..00000000000
--- a/library/cpp/pop_count/popcount.h
+++ /dev/null
@@ -1,105 +0,0 @@
-#pragma once
-
-#include <util/generic/typelist.h>
-#include <util/system/cpu_id.h>
-#include <util/system/defaults.h>
-#include <util/system/hi_lo.h>
-#include <util/system/platform.h>
-
-#if defined(_MSC_VER)
-#include <intrin.h>
-#endif
-
-static inline ui32 PopCountImpl(ui8 n) {
-#if defined(_ppc64_)
-    ui32 r;
-    __asm__("popcntb %0, %1"
-            : "=r"(r)
-            : "r"(n)
-            :);
-    return r;
-#else
-    extern ui8 const* PopCountLUT8;
-    return PopCountLUT8[n];
-#endif
-}
-
-static inline ui32 PopCountImpl(ui16 n) {
-#if defined(_MSC_VER)
-    return __popcnt16(n);
-#else
-    extern ui8 const* PopCountLUT16;
-    return PopCountLUT16[n];
-#endif
-}
-
-static inline ui32 PopCountImpl(ui32 n) {
-#if defined(_MSC_VER)
-    return __popcnt(n);
-#else
-#if defined(_x86_64_)
-    if (NX86::CachedHavePOPCNT()) {
-        ui32 r;
-
-        __asm__("popcnt %1, %0;"
-                : "=r"(r)
-                : "r"(n)
-                :);
-
-        return r;
-    }
-#else
-#if defined(_ppc64_)
-    ui32 r;
-
-    __asm__("popcntw %0, %1"
-            : "=r"(r)
-            : "r"(n)
-            :);
-
-    return r;
-#endif
-#endif
-
-    return PopCountImpl((ui16)Lo16(n)) + PopCountImpl((ui16)Hi16(n));
-#endif
-}
-
-static inline ui32 PopCountImpl(ui64 n) {
-#if defined(_MSC_VER) && !defined(_i386_)
-    return __popcnt64(n);
-#else
-#if defined(_x86_64_)
-    if (NX86::CachedHavePOPCNT()) {
-        ui64 r;
-
-        __asm__("popcnt %1, %0;"
-                : "=r"(r)
-                : "r"(n)
-                :);
-
-        return r;
-    }
-#else
-#if defined(_ppc64_)
-    ui32 r;
-
-    __asm__("popcntd %0, %1"
-            : "=r"(r)
-            : "r"(n)
-            :);
-
-    return r;
-#endif
-#endif
-
-    return PopCountImpl((ui32)Lo32(n)) + PopCountImpl((ui32)Hi32(n));
-#endif
-}
-
-template <class T>
-static inline ui32 PopCount(T n) {
-    using TCvt = TFixedWidthUnsignedInt<T>;
-
-    return PopCountImpl((TCvt)n);
-}
diff --git a/library/cpp/pop_count/popcount_ut.cpp b/library/cpp/pop_count/popcount_ut.cpp
deleted file mode 100644
index 5cd6605411f..00000000000
--- a/library/cpp/pop_count/popcount_ut.cpp
+++ /dev/null
@@ -1,70 +0,0 @@
-#include "popcount.h"
-
-#include <library/cpp/testing/unittest/registar.h>
-
-#include <util/random/random.h>
-
-Y_UNIT_TEST_SUITE(TestPopCount) {
-    template <class T>
-    static inline ui32 SlowPopCount(T t) {
-        ui32 ret = 0;
-
-        while (t) {
-            if (t & T(1)) {
-                ++ret;
-            }
-
-            t = t >> 1;
-        }
-
-        return ret;
-    }
-
-    template <class T>
-    static inline void Test() {
-        for (size_t i = 0; i < 10000; ++i) {
-            const T rndv = RandomNumber<T>();
-
-            UNIT_ASSERT_VALUES_EQUAL(SlowPopCount(rndv), PopCount(rndv));
-        }
-    }
-
-    Y_UNIT_TEST(Test8) {
-        Test<ui8>();
-    }
-
-    Y_UNIT_TEST(Test16) {
-        Test<ui16>();
-    }
-
-    Y_UNIT_TEST(Test32) {
-        Test<ui32>();
-    }
-
-    Y_UNIT_TEST(Test64) {
-        Test<ui64>();
-    }
-
-    Y_UNIT_TEST(TestPopCount) {
-        UNIT_ASSERT_VALUES_EQUAL(PopCount(0), 0);
-        UNIT_ASSERT_VALUES_EQUAL(PopCount(1), 1);
-        UNIT_ASSERT_VALUES_EQUAL(PopCount(1 << 10), 1);
-        UNIT_ASSERT_VALUES_EQUAL(PopCount((1 << 10) + 1), 2);
-        UNIT_ASSERT_VALUES_EQUAL(PopCount(0xFFFF), 16);
-        UNIT_ASSERT_VALUES_EQUAL(PopCount(0xFFFFFFFF), 32);
-        UNIT_ASSERT_VALUES_EQUAL(PopCount(0x55555555), 16);
-
-        UNIT_ASSERT_VALUES_EQUAL(0, PopCount(0ULL));
-        UNIT_ASSERT_VALUES_EQUAL(1, PopCount(1ULL));
-        UNIT_ASSERT_VALUES_EQUAL(16, PopCount(0xAAAAAAAAULL));
-        UNIT_ASSERT_VALUES_EQUAL(32, PopCount(0xFFFFFFFFULL));
-        UNIT_ASSERT_VALUES_EQUAL(32, PopCount(0xAAAAAAAAAAAAAAAAULL));
-        UNIT_ASSERT_VALUES_EQUAL(64, PopCount(0xFFFFFFFFFFFFFFFFULL));
-
-        ui64 v = 0;
-
-        for (int i = 0; i < 64; v |= 1ULL << i, ++i) {
-            UNIT_ASSERT_VALUES_EQUAL(i, PopCount(v));
-        }
-    }
-}
diff --git a/library/cpp/pop_count/ut/ya.make b/library/cpp/pop_count/ut/ya.make
deleted file mode 100644
index 179d47f064d..00000000000
--- a/library/cpp/pop_count/ut/ya.make
+++ /dev/null
@@ -1,7 +0,0 @@
-UNITTEST_FOR(library/cpp/pop_count)
-
-SRCS(
-    popcount_ut.cpp
-)
-
-END()
diff --git a/library/cpp/pop_count/ya.make b/library/cpp/pop_count/ya.make
deleted file mode 100644
index d858f3e87ec..00000000000
--- a/library/cpp/pop_count/ya.make
+++ /dev/null
@@ -1,12 +0,0 @@
-LIBRARY()
-
-SRCS(
-    popcount.cpp
-)
-
-END()
-
-RECURSE(
-    benchmark
-    ut
-)
diff --git a/library/cpp/string_utils/ztstrbuf/ztstrbuf_ut.cpp b/library/cpp/string_utils/ztstrbuf/ztstrbuf_ut.cpp
index d8215abdfad..b22d4bf216d 100644
--- a/library/cpp/string_utils/ztstrbuf/ztstrbuf_ut.cpp
+++ b/library/cpp/string_utils/ztstrbuf/ztstrbuf_ut.cpp
@@ -12,7 +12,7 @@ Y_UNIT_TEST_SUITE(TZtStringBufTest) {
     Y_UNIT_TEST(Constness) {
         constexpr TZtStringBuf s0{"bar"};
         static_assert(s0[0] == 'b');
-        static_assert(s0[3] == '\0');
+        static_assert(s0.data()[s0.size()] == '\0');
         static_assert(s0.data()[2] == 'r');
         UNIT_ASSERT_VALUES_EQUAL(s0, TString{"bar"});
     }
diff --git a/library/cpp/svnversion/ya.make b/library/cpp/svnversion/ya.make
index d028f45c94d..27e91546445 100644
--- a/library/cpp/svnversion/ya.make
+++ b/library/cpp/svnversion/ya.make
@@ -6,7 +6,7 @@ SRCS(
 )
 
 IF (OPENSOURCE_PROJECT == "yt-cpp-sdk")
-    PEERDIR(build/scripts/c_templates/)
+    PEERDIR(build/scripts/c_templates)
 ENDIF()
 
 END()
diff --git a/library/cpp/testing/common/env.cpp b/library/cpp/testing/common/env.cpp
index 13f3f186afd..67e081c371c 100644
--- a/library/cpp/testing/common/env.cpp
+++ b/library/cpp/testing/common/env.cpp
@@ -41,6 +41,10 @@ TString BinaryPath(TStringBuf path) {
 }
 
 TString GetArcadiaTestsData() {
+    if (GetEnv("USE_ATD_FROM_SNAPSHOT")) {
+        return ArcadiaSourceRoot() + "/atd_ro_snapshot";
+    }
+
     TString atdRoot = NPrivate::GetTestEnv().ArcadiaTestsDataDir;
     if (atdRoot) {
         return atdRoot;
diff --git a/library/cpp/testing/mock_server/ut/server_ut.cpp b/library/cpp/testing/mock_server/ut/server_ut.cpp
deleted file mode 100644
index 74b3dcec050..00000000000
--- a/library/cpp/testing/mock_server/ut/server_ut.cpp
+++ /dev/null
@@ -1,40 +0,0 @@
-#include <library/cpp/testing/mock_server/server.h>
-
-#include <library/cpp/http/simple/http_client.h>
-#include <library/cpp/testing/unittest/registar.h>
-
-Y_UNIT_TEST_SUITE(Server) {
-    int i;
-
-    Y_UNIT_TEST(pong) {
-        TPortManager pm;
-        ui16 port = pm.GetPort(80);
-        NMock::TMockServer server(port, []() { return new NMock::TPong; });
-
-        TKeepAliveHttpClient cl("localhost", port);
-        UNIT_ASSERT_VALUES_EQUAL(200, cl.DoGet("/ping"));
-        UNIT_ASSERT_VALUES_EQUAL(404, cl.DoGet("/kek"));
-    }
-
-    Y_UNIT_TEST(custom) {
-        class TCustomReplier: public TRequestReplier {
-        public:
-            bool DoReply(const TReplyParams& params) override {
-                THttpResponse resp(HttpCodes::HTTP_OK);
-                resp.SetContent("everithing is ok");
-                resp.OutTo(params.Output);
-
-                return true;
-            }
-        };
-
-        TPortManager pm;
-        ui16 port = pm.GetPort(80);
-        NMock::TMockServer server(port, []() { return new TCustomReplier; });
-
-        TKeepAliveHttpClient cl("localhost", port);
-        TStringStream out;
-        UNIT_ASSERT_VALUES_EQUAL(200, cl.DoGet("/foo", &out));
-        UNIT_ASSERT_VALUES_EQUAL("everithing is ok", out.Str());
-    }
-}
diff --git a/library/cpp/testing/mock_server/ut/ya.make b/library/cpp/testing/mock_server/ut/ya.make
deleted file mode 100644
index f4ee34458fc..00000000000
--- a/library/cpp/testing/mock_server/ut/ya.make
+++ /dev/null
@@ -1,11 +0,0 @@
-UNITTEST_FOR(library/cpp/testing/mock_server)
-
-PEERDIR(
-    library/cpp/http/simple
-)
-
-SRCS(
-    server_ut.cpp
-)
-
-END()
diff --git a/library/cpp/tld/tlds-alpha-by-domain.txt b/library/cpp/tld/tlds-alpha-by-domain.txt
index 75edec6f550..dc6477cc73f 100644
--- a/library/cpp/tld/tlds-alpha-by-domain.txt
+++ b/library/cpp/tld/tlds-alpha-by-domain.txt
@@ -1,4 +1,4 @@
-# Version 2024111300, Last Updated Wed Nov 13 07:07:01 2024 UTC
+# Version 2024111900, Last Updated Tue Nov 19 07:07:01 2024 UTC
 AAA
 AARP
 ABB
diff --git a/library/cpp/yt/misc/cast-inl.h b/library/cpp/yt/misc/cast-inl.h
index 50920f01934..5e5a0d90eea 100644
--- a/library/cpp/yt/misc/cast-inl.h
+++ b/library/cpp/yt/misc/cast-inl.h
@@ -119,7 +119,7 @@ T CheckedIntegralCast(S value)
 
 template <class T, class S>
     requires TEnumTraits<T>::IsEnum
-constexpr std::optional<T> TryCheckedEnumCast(S value)
+constexpr std::optional<T> TryCheckedEnumCast(S value, bool enableUnknown)
 {
     auto underlying = TryCheckedIntegralCast<std::underlying_type_t<T>>(value);
     [[unlikely]] if (!underlying) {
@@ -127,6 +127,15 @@ constexpr std::optional<T> TryCheckedEnumCast(S value)
     }
     auto candidate = static_cast<T>(*underlying);
     [[unlikely]] if (!TEnumTraits<T>::IsValidValue(candidate)) {
+        if (enableUnknown) {
+            if constexpr (constexpr auto optionalUnknownValue = TEnumTraits<T>::TryGetUnknownValue()) {
+                if constexpr (TEnumTraits<T>::IsBitEnum) {
+                    return static_cast<T>(*underlying & ToUnderlying(TEnumTraits<T>::GetAllSetValue())) | *optionalUnknownValue;
+                } else {
+                    return *optionalUnknownValue;
+                }
+            }
+        }
         return std::nullopt;
     }
     return candidate;
@@ -136,7 +145,7 @@ template <class T, class S>
     requires TEnumTraits<T>::IsEnum
 T CheckedEnumCast(S value)
 {
-    auto result = TryCheckedEnumCast<T>(value);
+    auto result = TryCheckedEnumCast<T>(value, /*enableUnknown*/ true);
     [[unlikely]] if (!result) {
         if constexpr (std::is_signed_v<S>) {
             throw TSimpleException(Sprintf("Error casting %s value \"%" PRIi64 "\" to enum %s",
diff --git a/library/cpp/yt/misc/cast.h b/library/cpp/yt/misc/cast.h
index a4e32e0287d..ccf1eb21a6b 100644
--- a/library/cpp/yt/misc/cast.h
+++ b/library/cpp/yt/misc/cast.h
@@ -26,7 +26,7 @@ T CheckedIntegralCast(S value);
 
 template <class T, class S>
     requires TEnumTraits<T>::IsEnum
-constexpr std::optional<T> TryCheckedEnumCast(S value);
+constexpr std::optional<T> TryCheckedEnumCast(S value, bool enableUnknown = false);
 
 template <class T, class S>
     requires TEnumTraits<T>::IsEnum
diff --git a/library/cpp/yt/misc/unittests/cast_ut.cpp b/library/cpp/yt/misc/unittests/cast_ut.cpp
index 8662575d6c0..e6f5409f2ff 100644
--- a/library/cpp/yt/misc/unittests/cast_ut.cpp
+++ b/library/cpp/yt/misc/unittests/cast_ut.cpp
@@ -21,6 +21,26 @@ DEFINE_BIT_ENUM_WITH_UNDERLYING_TYPE(EFeatures, ui8,
     ((Second)(0x0002))
 );
 
+DEFINE_BIT_ENUM(ELangsWithUnknown,
+    ((None)       (0x00))
+    ((Cpp)        (0x01))
+    ((Go)         (0x02))
+    ((Rust)       (0x04))
+    ((Python)     (0x08))
+    ((JavaScript) (0x10))
+    ((CppGo)      (0x03))
+    ((All)        (0x1f))
+    ((Unknown)    (0x20))
+);
+DEFINE_ENUM_UNKNOWN_VALUE(ELangsWithUnknown, Unknown);
+
+DEFINE_ENUM(EColorWithUnknown,
+    ((Red)     (0))
+    ((Green)   (1))
+    ((Unknown) (2))
+);
+DEFINE_ENUM_UNKNOWN_VALUE(EColorWithUnknown, Unknown);
+
 TEST(TCastTest, TryCheckedEnumCast)
 {
     EXPECT_EQ((TryCheckedEnumCast<ECardinal, char>(2)), ECardinal::East);
@@ -36,6 +56,35 @@ TEST(TCastTest, TryCheckedEnumCast)
     EXPECT_EQ((TryCheckedEnumCast<EFeatures, ui8>(ToUnderlying(EFeatures::First | EFeatures::Second))), EFeatures::First | EFeatures::Second);
 
     EXPECT_FALSE((TryCheckedEnumCast<EFeatures, ui8>(0x10)));
+
+    EXPECT_FALSE(TryCheckedEnumCast<EColorWithUnknown>(3));
+    EXPECT_EQ(TryCheckedEnumCast<EColorWithUnknown>(3, /*enableUnknown*/ true), EColorWithUnknown::Unknown);
+
+    EXPECT_FALSE(TryCheckedEnumCast<ELangsWithUnknown>(0x40));
+    EXPECT_EQ(TryCheckedEnumCast<ELangsWithUnknown>(0x40, /*enableUnknown*/ true), ELangsWithUnknown::Unknown);
+    EXPECT_EQ(TryCheckedEnumCast<ELangsWithUnknown>(0x41, /*enableUnknown*/ true), ELangsWithUnknown::Unknown | ELangsWithUnknown::Cpp);
+}
+
+TEST(TCastTest, CheckedEnumCast)
+{
+    EXPECT_EQ((CheckedEnumCast<ECardinal, char>(2)), ECardinal::East);
+    EXPECT_EQ((CheckedEnumCast<ECardinal, int>(3)), ECardinal::South);
+
+    EXPECT_THROW((CheckedEnumCast<ECardinal, char>(100)), TSimpleException);
+    EXPECT_THROW((CheckedEnumCast<ECardinal, int>(300)), TSimpleException);
+
+    EXPECT_EQ((CheckedEnumCast<EFeatures, ui8>(0)), EFeatures::None);
+    EXPECT_EQ((CheckedEnumCast<EFeatures, ui8>(ToUnderlying(EFeatures::First))), EFeatures::First);
+    EXPECT_EQ((CheckedEnumCast<EFeatures, ui8>(ToUnderlying(EFeatures::Second))), EFeatures::Second);
+    EXPECT_EQ((CheckedEnumCast<EFeatures, int>(ToUnderlying(EFeatures::First))), EFeatures::First);
+    EXPECT_EQ((CheckedEnumCast<EFeatures, ui8>(ToUnderlying(EFeatures::First | EFeatures::Second))), EFeatures::First | EFeatures::Second);
+
+    EXPECT_THROW((CheckedEnumCast<EFeatures, ui8>(0x10)), TSimpleException);
+
+    EXPECT_EQ(CheckedEnumCast<EColorWithUnknown>(3), EColorWithUnknown::Unknown);
+
+    EXPECT_EQ(CheckedEnumCast<ELangsWithUnknown>(0x40), ELangsWithUnknown::Unknown);
+    EXPECT_EQ(CheckedEnumCast<ELangsWithUnknown>(0x41), ELangsWithUnknown::Unknown | ELangsWithUnknown::Cpp);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/library/cpp/yt/string/format-inl.h b/library/cpp/yt/string/format-inl.h
index 7f1f7259665..e90d68bfe12 100644
--- a/library/cpp/yt/string/format-inl.h
+++ b/library/cpp/yt/string/format-inl.h
@@ -871,12 +871,43 @@ concept CFormatter = CInvocable<T, void(size_t, TStringBuilderBase*, TStringBuf)
 ////////////////////////////////////////////////////////////////////////////////
 
 template <CFormatter TFormatter>
-void RunFormatter(
+void RunFormatterAt(
+    const TFormatter& formatter,
+    size_t index,
+    TStringBuilderBase* builder,
+    TStringBuf spec,
+    bool singleQuotes,
+    bool doubleQuotes)
+{
+    // 'n' means 'nothing'; skip the argument.
+    if (!spec.Contains('n')) {
+        if (singleQuotes) {
+            builder->AppendChar('\'');
+        }
+        if (doubleQuotes) {
+            builder->AppendChar('"');
+        }
+
+        formatter(index, builder, spec);
+
+        if (singleQuotes) {
+            builder->AppendChar('\'');
+        }
+        if (doubleQuotes) {
+            builder->AppendChar('"');
+        }
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <CFormatter TFormatter>
+void RunFormatterFullScan(
     TStringBuilderBase* builder,
     TStringBuf format,
-    const TFormatter& formatter)
+    const TFormatter& formatter,
+    int argIndex = 0)
 {
-    size_t argIndex = 0;
     auto current = std::begin(format);
     auto end = std::end(format);
     while (true) {
@@ -912,27 +943,13 @@ void RunFormatter(
         bool singleQuotes = false;
         bool doubleQuotes = false;
 
+        static constexpr TStringBuf conversionSpecifiers =
+            "diuoxXfFeEgGaAcspn";
+
         while (
             argFormatEnd != end &&
-            *argFormatEnd != GenericSpecSymbol &&     // value in generic format
-            *argFormatEnd != 'd' &&                   // others are standard specifiers supported by printf
-            *argFormatEnd != 'i' &&
-            *argFormatEnd != 'u' &&
-            *argFormatEnd != 'o' &&
-            *argFormatEnd != 'x' &&
-            *argFormatEnd != 'X' &&
-            *argFormatEnd != 'f' &&
-            *argFormatEnd != 'F' &&
-            *argFormatEnd != 'e' &&
-            *argFormatEnd != 'E' &&
-            *argFormatEnd != 'g' &&
-            *argFormatEnd != 'G' &&
-            *argFormatEnd != 'a' &&
-            *argFormatEnd != 'A' &&
-            *argFormatEnd != 'c' &&
-            *argFormatEnd != 's' &&
-            *argFormatEnd != 'p' &&
-            *argFormatEnd != 'n')
+            *argFormatEnd != GenericSpecSymbol &&            // value in generic format
+            !conversionSpecifiers.Contains(*argFormatEnd)) // others are standard specifiers supported by printf
         {
             switch (*argFormatEnd) {
                 case 'q':
@@ -952,27 +969,162 @@ void RunFormatter(
             ++argFormatEnd;
         }
 
-        // 'n' means 'nothing'; skip the argument.
-        if (*argFormatBegin != 'n') {
-            // Format argument.
-            TStringBuf argFormat(argFormatBegin, argFormatEnd);
-            if (singleQuotes) {
-                builder->AppendChar('\'');
-            }
-            if (doubleQuotes) {
-                builder->AppendChar('"');
-            }
-            formatter(argIndex++, builder, argFormat);
-            if (singleQuotes) {
-                builder->AppendChar('\'');
-            }
-            if (doubleQuotes) {
-                builder->AppendChar('"');
+        RunFormatterAt(
+            formatter,
+            argIndex++,
+            builder,
+            TStringBuf{argFormatBegin, argFormatEnd},
+            singleQuotes,
+            doubleQuotes);
+
+        current = argFormatEnd;
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <CFormatter TFormatter, class... TArgs>
+void RunFormatter(
+    TStringBuilderBase* builder,
+    TBasicFormatString<TArgs...> formatString,
+    const TFormatter& formatter)
+{
+    auto isValidLocations = [] (const auto& t) {
+        return std::get<0>(t) != std::get<1>(t);
+    };
+    // Generally marker is simply "%v" e.g. 2 symbols.
+    // We assume it is used to insert something for roughly 5 symbols
+    // of size.
+    builder->Preallocate(std::size(formatString.Get()) + sizeof...(TArgs) * (5 - 2));
+
+    // Empty marker positions -- fallback to the normal impl.
+    if constexpr (sizeof...(TArgs) != 0) {
+        if (!isValidLocations(formatString.Markers[0])) {
+            RunFormatterFullScan(builder, formatString.Get(), formatter);
+            return;
+        }
+    } else {
+        if (formatString.Escapes[0] == -2) {
+            RunFormatterFullScan(builder, formatString.Get(), formatter);
+            return;
+        }
+    }
+
+    int escapesFound = 0;
+    int currentPos = 0;
+
+    auto beginIt = formatString.Get().begin();
+    auto size = formatString.Get().size();
+
+    const auto& [markers, escapes] = std::tie(formatString.Markers, formatString.Escapes);
+
+    auto appendVerbatim = [&] (int offsetToEnd) {
+        builder->AppendString(TStringBuf{beginIt + currentPos, beginIt + offsetToEnd});
+    };
+
+    auto processEscape = [&] () mutable {
+        // OpenMP doesn't support structured bindings :(.
+        auto escapePos = formatString.Escapes[escapesFound];
+
+        // Append everything that's present until %%.
+        appendVerbatim(escapePos);
+
+        // Append '%'.
+        builder->AppendChar('%');
+
+        // Advance position to first '%' pos + 2.
+        currentPos = escapePos + 2;
+    };
+
+    int argIndex = 0;
+
+    while(argIndex < std::ssize(markers)) {
+        auto [markerStart, markerEnd] = markers[argIndex];
+
+        if (
+            escapes[escapesFound] != -1 &&
+            escapes[escapesFound] - currentPos < markerStart - currentPos)
+        {
+            // Escape sequence is closer.
+            processEscape();
+            ++escapesFound;
+        } else {
+            // Normal marker is closer.
+
+            // Append everything that's present until marker start.
+            appendVerbatim(markerStart);
+
+            // Parsing format string.
+
+            // We skip '%' here since spec does not contain it.
+            auto spec = TStringBuf{beginIt + markerStart + 1, beginIt + markerEnd};
+            bool singleQuotes = false;
+            bool doubleQuotes = false;
+            for (auto c : spec) {
+                if (c == 'q') {
+                    singleQuotes = true;
+                }
+                if (c == 'Q') {
+                    doubleQuotes = true;
+                }
             }
+            RunFormatterAt(
+                formatter,
+                argIndex,
+                builder,
+                spec,
+                singleQuotes,
+                doubleQuotes);
+
+            // Advance position past marker's end.
+            currentPos = markerEnd;
+            ++argIndex;
+            continue;
         }
 
-        current = argFormatEnd;
+        // Check if the number of escapes we have found has exceeded the recorded limit
+        // e.g. we have to manually scan the rest of the formatString.
+        if (escapesFound == std::ssize(escapes)) {
+            break;
+        }
     }
+
+    // Process remaining escapes.
+    while (escapesFound < std::ssize(escapes)) {
+        if (escapes[escapesFound] == -1) {
+            break;
+        }
+
+        processEscape();
+        ++escapesFound;
+    }
+
+    // We either ran out of markers or reached the limit of allowed
+    // escape sequences.
+
+    // Happy path: no limit on escape sequences.
+    if (escapesFound != std::ssize(escapes)) {
+        // Append whatever's left until the end.
+        appendVerbatim(size);
+        return;
+    }
+
+    // Sad path: we have to fully parse remainder of format.
+    RunFormatterFullScan(builder, TStringBuf{beginIt + currentPos, beginIt + size}, formatter, argIndex);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+// For benchmarking purposes.
+template <class... TArgs>
+TString FormatOld(TFormatString<TArgs...> format, TArgs&&... args)
+{
+    TStringBuilder builder;
+    if constexpr ((CFormattable<TArgs> && ...)) {
+        NYT::NDetail::TValueFormatter<0, TArgs...> formatter(args...);
+        NYT::NDetail::RunFormatterFullScan(&builder, format.Get(), formatter);
+    }
+    return builder.Flush();
 }
 
 } // namespace NDetail
@@ -991,7 +1143,7 @@ void Format(TStringBuilderBase* builder, TFormatString<TArgs...> format, TArgs&&
     // a second error.
     if constexpr ((CFormattable<TArgs> && ...)) {
         NYT::NDetail::TValueFormatter<0, TArgs...> formatter(args...);
-        NYT::NDetail::RunFormatter(builder, format.Get(), formatter);
+        NYT::NDetail::RunFormatter(builder, format, formatter);
     }
 }
 
@@ -1012,7 +1164,7 @@ void FormatVector(
     const TVector& vec)
 {
     NYT::NDetail::TRangeFormatter<typename TVector::value_type> formatter(vec);
-    NYT::NDetail::RunFormatter(builder, format, formatter);
+    NYT::NDetail::RunFormatterFullScan(builder, format, formatter);
 }
 
 template <class TVector>
@@ -1022,7 +1174,7 @@ void FormatVector(
     const TVector& vec)
 {
     NYT::NDetail::TRangeFormatter<typename TVector::value_type> formatter(vec);
-    NYT::NDetail::RunFormatter(builder, format, formatter);
+    NYT::NDetail::RunFormatterFullScan(builder, format, formatter);
 }
 
 template <size_t Length, class TVector>
diff --git a/library/cpp/yt/string/format_analyser.h b/library/cpp/yt/string/format_analyser.h
index 20eee605809..9f194144dcb 100644
--- a/library/cpp/yt/string/format_analyser.h
+++ b/library/cpp/yt/string/format_analyser.h
@@ -4,6 +4,7 @@
 
 #include <util/generic/strbuf.h>
 
+#include <algorithm>
 #include <array>
 #include <string_view>
 
@@ -14,13 +15,26 @@ namespace NYT::NDetail {
 struct TFormatAnalyser
 {
 public:
+    using TMarkerLocation = std::tuple<int, int>;
+    // NB(arkady-e1ppa): Location is considered invalid (e.g. not filled)
+    // if get<0> == get<1> == 0.
+    template <class... TArgs>
+    using TMarkerLocations = std::array<TMarkerLocation, sizeof...(TArgs)>;
+    // NB(arkady-e1ppa): We can't cover all of them since that would require
+    // dynamic storage for their coordinates and we do not have
+    // constexpr context large enough to deallocate dynamic memory at the
+    // correct time. Thus we store first 5 position and scanning afterwards
+    // is pessimized. |-1| is for no position at all.
+    // |-2| is used to imply runtime format.
+    using TEscapeLocations = std::array<int, 5>;
+
     // TODO(arkady-e1ppa): Until clang-19 consteval functions
     // defined out of line produce symbols in rare cases
     // causing linker to crash.
     template <class... TArgs>
-    static consteval void ValidateFormat(std::string_view fmt)
+    static consteval auto AnalyzeFormat(std::string_view fmt)
     {
-        DoValidateFormat<TArgs...>(fmt);
+        return DoAnalyzeFormat<TArgs...>(fmt);
     }
 
 private:
@@ -51,11 +65,16 @@ private:
     static constexpr char IntroductorySymbol = '%';
 
     template <class... TArgs>
-    static consteval void DoValidateFormat(std::string_view format)
+    static consteval auto DoAnalyzeFormat(std::string_view format)
     {
-        std::array<std::string_view, sizeof...(TArgs)> markers = {};
         std::array<TSpecifiers, sizeof...(TArgs)> specifiers{GetSpecifiers<TArgs>()...};
 
+        TMarkerLocations<TArgs...> markerLocations = {};
+        TEscapeLocations escapeLocations = {};
+        std::ranges::fill(escapeLocations, -1);
+
+        int escapesCount = 0;
+
         int markerCount = 0;
         int currentMarkerStart = -1;
 
@@ -81,12 +100,17 @@ private:
                     throw "You may not terminate flag sequence other than %% with \'%\' symbol";
                 }
                 // '%%' detected --- skip
+                if (escapesCount < std::ssize(escapeLocations)) {
+                    escapeLocations[escapesCount] = currentMarkerStart;
+                    ++escapesCount;
+                }
+
                 currentMarkerStart = -1;
                 continue;
             }
 
             // We are inside of marker.
-            if (markerCount == std::ssize(markers)) {
+            if (markerCount == std::ssize(markerLocations)) {
                 // Too many markers
                 throw "Number of arguments supplied to format is smaller than the number of flag sequences";
             }
@@ -94,8 +118,8 @@ private:
             if (Contains(specifiers[markerCount].Conversion, symbol)) {
                 // Marker has finished.
 
-                markers[markerCount]
-                    = std::string_view(format.begin() + currentMarkerStart, index - currentMarkerStart + 1);
+                markerLocations[markerCount]
+                    = std::tuple{currentMarkerStart, index + 1};
                 currentMarkerStart = -1;
                 ++markerCount;
 
@@ -110,16 +134,16 @@ private:
         if (currentMarkerStart != -1) {
             // Runaway marker.
             throw "Unterminated flag sequence detected; Use \'%%\' to type plain %";
-            return;
         }
 
-        if (markerCount < std::ssize(markers)) {
+        if (markerCount < std::ssize(markerLocations)) {
             // Missing markers.
             throw "Number of arguments supplied to format is greater than the number of flag sequences";
         }
 
         // TODO(arkady-e1ppa): Consider per-type verification
         // of markers.
+        return std::tuple(markerLocations, escapeLocations);
     }
 };
 
diff --git a/library/cpp/yt/string/format_arg.h b/library/cpp/yt/string/format_arg.h
index 544e2657667..4dc7be06e8f 100644
--- a/library/cpp/yt/string/format_arg.h
+++ b/library/cpp/yt/string/format_arg.h
@@ -32,7 +32,7 @@ class TFormatArgBase
 public:
     // TODO(arkady-e1ppa): Consider more strict formatting rules.
     static constexpr std::array ConversionSpecifiers = {
-        'v', '1', 'c', 's', 'd', 'i', 'o',
+        'v', 'c', 's', 'd', 'i', 'o',
         'x', 'X', 'u', 'f', 'F', 'e', 'E',
         'a', 'A', 'g', 'G', 'n', 'p'
     };
diff --git a/library/cpp/yt/string/format_string-inl.h b/library/cpp/yt/string/format_string-inl.h
index a692d9648d0..67f9bad45c9 100644
--- a/library/cpp/yt/string/format_string-inl.h
+++ b/library/cpp/yt/string/format_string-inl.h
@@ -4,6 +4,8 @@
 #include "format_string.h"
 #endif
 
+#include <algorithm>
+
 namespace NYT {
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -15,8 +17,13 @@ consteval TBasicFormatString<TArgs...>::TBasicFormatString(const T& fmt)
     : Format_(fmt)
 {
     CheckFormattability();
-#if !defined(NDEBUG) && !defined(YT_DISABLE_FORMAT_STATIC_ANALYSIS)
-    NDetail::TFormatAnalyser::ValidateFormat<std::remove_cvref_t<TArgs>...>(Format_);
+#if !defined(YT_DISABLE_FORMAT_STATIC_ANALYSIS)
+    std::tie(Markers, Escapes) = NDetail::TFormatAnalyser::AnalyzeFormat<std::remove_cvref_t<TArgs>...>(Format_);
+#else
+    std::ranges::fill_n(std::ranges::begin(Escapes), 1, -1);
+    if constexpr (sizeof...(TArgs) != 0) {
+        std::ranges::fill_n(std::ranges::begin(Markers), 1, std::tuple{0, 0});
+    }
 #endif
 }
 
@@ -46,6 +53,11 @@ template <class... TArgs>
 TBasicFormatString<TArgs...>::TBasicFormatString(TRuntimeFormat fmt)
     : Format_(fmt.Get())
 {
+    std::ranges::fill_n(std::ranges::begin(Escapes), 1, -1);
+    if constexpr (sizeof...(TArgs) != 0) {
+        std::ranges::fill_n(std::ranges::begin(Markers), 1, std::tuple{0, 0});
+    }
+
     // NB(arkady-e1ppa): StaticFormat performs the
     // formattability check of the args in a way
     // that provides more useful information
diff --git a/library/cpp/yt/string/format_string.h b/library/cpp/yt/string/format_string.h
index 786c2e39ed5..1008ccb4533 100644
--- a/library/cpp/yt/string/format_string.h
+++ b/library/cpp/yt/string/format_string.h
@@ -43,6 +43,10 @@ public:
 
     static consteval void CheckFormattability();
 
+    // Data used for compile-time slicing of the format string.
+    NDetail::TFormatAnalyser::TMarkerLocations<TArgs...> Markers = {};
+    NDetail::TFormatAnalyser::TEscapeLocations Escapes = {};
+
 private:
     std::string_view Format_;
 
diff --git a/library/cpp/yt/string/unittests/format_ut.cpp b/library/cpp/yt/string/unittests/format_ut.cpp
index ac3be99ad97..8aca8c8e290 100644
--- a/library/cpp/yt/string/unittests/format_ut.cpp
+++ b/library/cpp/yt/string/unittests/format_ut.cpp
@@ -326,6 +326,11 @@ TEST(TFormatTest, CustomFlagsCollectionTwoLevels)
     EXPECT_EQ(Format("%NRv", arr), toCollectionD2("RNP"));
 }
 
+TEST(TFormatTest, ManyEscapes)
+{
+    EXPECT_EQ("a%b%c%d%e%f%g", Format("%v%%%v%%%v%%%v%%%v%%%v%%%g", "a", "b", "c", "d", "e", "f", "g"));
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 } // namespace